On 2/19/21 1:52 AM, Asherah Connor wrote:
This patch adds preliminary support for the QEMU firmware interface (aka. QEMU fw_cfg) on the Arm platform. I'm sending this to see if there's interest in accepting this support; ultimately, I'd like to get the QEMU "ramfb" display working, which requires the use of fw_cfg to configure.
Please note this is my first attempt at adding functionality to U-Boot and there are likely to be many mistakes. Among others:
I've added this to arch_early_init_r, mimicking the existing support in arch/x86/cpu/qemu/qemu.c. Let me know if this is incorrect.
I am unsure about the Kconfig changes. These make qemu_arm64_defconfig work out of the box. It can still be disabled and build correctly. I've implied only "QFW" because the command wouldn't be necessary for e.g. future ramfb support. We may want to give the option a description in that case---it is currently considered "hidden" and only selected when "CMD_QFW" is.
I would be happy to maintain this going forward. Let me know if I should submit a patch for MAINTAINTERS.
Hello Asherah,
thank you for addressing the missing GPU support when running under QEMU ARM.
virtio-gpu is an alternative to ramfb. Why are you targeting ramfb and not virtio-gpu? Which impact does it have on the guest OS?
Best regards
Heinrich
Asherah Connor (1): arm: qemu: support qfw
arch/arm/Kconfig | 1 + arch/arm/Makefile | 1 + arch/arm/mach-qemu/Kconfig | 2 + arch/arm/mach-qemu/Makefile | 1 + arch/arm/mach-qemu/qemu.c | 109 ++++++++++++++++++++++++++++++++++++ 5 files changed, 114 insertions(+) create mode 100644 arch/arm/mach-qemu/Makefile create mode 100644 arch/arm/mach-qemu/qemu.c